On the Analysis of Co-occurrence of Anti-patterns and Clones

In software engineering, a smell is a part of a software system's source code with a poor quality and that may indicate a deeper problem. Although many kinds of smells have been studied to analyze their causes, their behavior, and their impact on software quality, those smells typically are studied independently from each other. However, if two smells coincide inside a class, this could increases their negative effect (e.g., spaghetti code that is being cloned across the system). In this paper we report results from an empirical study conducted to examine the relationship between two specific kinds of smells: code clones and anti-patterns. We conducted our study on three open-source software systems: Azureus, Eclipse, and JHotDraw. Results show that between 32% and 63% of classes in the analysed systems present co-occurrence of smells, and that such classes are more risky in term of fault-proneness.